Push-button fly-blade knife and a method for making the same



April 12, 1955 Filed July 28, 1949 M. A. PUSH-BUTTON F RANDO BLADE KNIFEA METHOD FOR MAKING THE SAME AND 3 Sheets-Sheet l INVENTOR. M 4 '7-fimwvo 4 TTOE VEY April 1955 M. A. MIRANDO 2,705,832

PUSH-BUTTON FLY-BLADE KNIFE AND A METHOD FOR MAKING THE SAME Filed July28, 1949 3 sheets-Sheet 2 96 .1 v INVENTOR- T1 1: :5 W M25100 t: g z i 4TTOEA/EY Aplll 12, 1955 MIRANDO 2,705,832

PUSH-BUTTON FLY-BLADE KNIFE AND A METHOD FOR MAKING THE SAME Filed July28, 1949 3 Sheets-Sheet 3 Q i l l 0 :r 100- 80; 32 3 4 55 9Q, X

IN V EN TOR. M 761. 17. 'MRg /p A rroz/vfy United States PatentPUSH-BUTTON FLY-BLADE KNIFE AND A lVIETHOlD FOR MAKING THE SAME MichaelA. Mirando, Providence, R. I., assignor to Imperial Knife Company, Inc.,Providence, R. I., a corporation of Rhode Island Application July 28,1949, Serial No. 107,310

9 Claims. (Cl. 30-159) This invention relates to a push-button fiy-bladeknife and a method for making the same.

At the present time knives of this character are considerably moreexpensive than knives having conventional, manually-openable blades, thedifference in cost arising from the several extra machine operationsrequired and the close tolerances to which the blade locking parts mustbe held.

For example, it presently is standard practice in the manufacture offly-blades for push-button knives, to mill indentations on both sides ofthe pivot opening in the tangs. These indentations are not aligned, yetmust be accurately positioned, and it therefore is necessary carefullyto set up each blade in a milling machine twice.

It is an object of the present invention to provide a blade constructionof the character described which permits of more rapid and economicalfabrication.

Milled blades further are subjected to the drawback that theindentations cannot be made deep enough to afford a sufficiently firmlock. A milling cutter inherently forms an arcuate locking indentationwhose effectiveness is a function of its maximum depth. If a millingcutter of very small radius is used, the teeth wear out too quickly.However, as the radius of the cutter is increased, the indentationbecomes longer and too long an indentation is undesirable, since it isvisible when the blade is open. Accordingly, it has been the custom tocompromise between the length and depth of the indentation. As a result,locking indentations in present-day knives are insuificiently deep.

It is another object of the invention to provide a knife blade andmethod for making the same wherein the depth of the indentation has norelationship to its length, so that the indentation may be madesuificiently deep to afford as firm a lock as is desired without havingthe same visible when the blade is open.

It now is the custom to employ a wedge-shaped locking lever in order (a)to dispose the push button perpendicular to the knife scale, (b) toobtain a substantial depth of engagement between the locking dog and thelocking indentation, and (c) to provide sufiicient clearance for thesafety catch. A locking lever of this shape is relatively expensive tomake. To reduce costs, it has been proposed to use sheet metal lockinglevers. However, this latter type of locking lever has provenunsatisfactory and is not used in quality knives of the characterdescribed because it causes the push button to be cocked when idle andsecures too shallow an engagement between the locking dog andindentation.

It is a further object of the invention to provide a knife of thecharacter described wherein the locking lever is made of sheet metal,thus reducing the cost of the knife, and wherein said locking lever isof such construction that a satisfactory engagement of the dog andproper location of the push button is effected.

Other objects of the invention will in part be obvious and in part willbe pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements and arrangements of parts which will beexemplified in the device hereinafter described and of which the scopeof application will be indicated in the appended claims.

In the accompanying drawings in which is shown one of the variouspossible embodiments of the invention,

Fig. 1 is a longitudinal sectional view through an 2,705,832 PatentedApr. 12, 1955 apparatus used in manufacturing knife blades in accordancewith the invention;

Figs. 2, 3, 4 and'S are sectional views taken substantially along thelines 2-2, 33, 4-4 and 55, respectively, of the apparatus shown in Fig.1;

Fig. 6 is a plan view of a knife blank as it appears upon leaving theapparatus of Fig. 1;

. Fig. 7 is a similar view of the knife blade after grind- 111g;

Fig. 8 is a sectional view taken substantially along the line 88 of Fig.7;

Fig. 9 is a plan view of the side plate of a push-button, fly-bladeknife frame;

Fig. 10 is a plan view of a push-button fly-blade knife frame as itappears with the locking lever, locking spring, safety catch and scaleremoved;

Fig. 11 is an edge view of the knife frame shown in Fig. 10;

Figure 12 is a perspective view of a locking lever embodying theinvention and adapted to be mounted on the knife frame shown in Figs. 10and 11;

Fig. 13 is a perspective view of a locking spring adapted to be mountedon the knife frame shown in Figs. 10 and 11;

Fig. 14 is a plan view of a complete push-button fiy-blade knifeembodying the invention;

Fig. 15 is an edge view of said knife;

Fig. 16 is an enlarged sectional view taken substantially along the line1616 of Fig. 14, the safety catch being shown in on position;

Fig. 17 is a sectional view taken substantially along the line 1717 ofFig. 15;

Fig. 18 is a view similar to Fig. 16, but showing the safety catch inoff position;

Fig. 19 is a view similar to Fig. 14, but with the scale removed betterto illustrate the locking lever, locking spring and safety catch.

Referring now in detail to the drawings, and more particularly to Figs.7-19, the reference numeral 20 denotes a push-button fly-blade knifeconstructed in accordance with the invention. As is conventional, saidknife comprises a frame 22 and a pair of covering scales 24, 26.

The frame includes two side plates 28, 30 which may, as is standard,have identical registering peripheries.

'Said plates are disposed on opposite sides of a spacer black 32 at theback of the frame and are held in this position by several rivets 34whose shanks pass through registered openings in the side plates andspacer and whose ends are headed.

The scales are of any suitable construction and configuration. By way ofexample, said scales may be of the type shown and described in UnitedStates Letters Patent No. 2,170,537 issued to Felix A. Mirando and HenryVossler on August 22, 1939, and owned by the assignee of the presentapplication. As thus constructed, each scale includes a pair of hollowsheet metal bolsters 36, 36 interconnected by an arched elongated insetstrip 33 in one piece with the bolsters. The strip supports anornamental flexible plastic covering 40 whose longitudinal edges aretucked under the strip. Projecting from opposite ends of the bolstersare tabs 40, 42 which are folded into pockets 44 provided on the tips ofthe knife frame. The edges of the scales desirably are in registry withthe underlying edges of the knife frame.

The knife includes a blade 46 having a tang 48 and a cutting portion 50.The tang is fashioned with a through opening 52 through which a pivotrivet 54 passes. Said rivet also extends through registered apertures inthe side plates 28, 30, the ends of the rivet being headed so that theblade is captively and pivotally secured to the knife frame.

Means is provided to bias the blade from closed to open position. Saidmeans comprises a conventional fly spring 56 constituting a strip offiat spring steel having an end formed with a depression 58 which iscaught between the block 32 and a rivet 60, the latter being secured tothe two side plates 28, 30. The other and free end of the fly spring islocated near the blade tang 48. In its unstressed position said free endis remote from the spacer 32, as shown in Fig. 19. This end normally isforced against the spacer by the edge 62 of the blade tang which isconcealed when the blade is closed (see Fig. 17) so that the fly springis flexed upon closing of the blade and the energy stored thereby servesto flip the blade to open position when the blade is released.

The knife further includes means to lock the blade in closed or openposition. Said means comprises two locking indentations 64, 66 in thetang of the blade, a locking lever 68 and a locking spring 70.

The'locking lever is fabricated from a flat strip of metal which isformed into a shape best shown in Figs. 12, 16 and 18. In its finishedcontour said locking lever includes an arch 72 from both sides of whichstraight reaches 74, 76 extend. To distinguish therebetween, the reach76 which extends toward the pivot rivet 54 hereinafter will be referredto as the front reach and the other reach 74 as the rear reach. Thefront reach terminates in a locking dog 78 which is offset so as to bedisposed at a level more inwardly of the knife frame than said reach 76.The rear reach is oriented at a slight angle with respect to the frontreach, being so arranged as to slope outwardly with respect to the knifeframe. Said rear reach terminates in a platform 78' parallel to andoffset outwardly from the front reach. Said platform carries a pushbutton 80.

The side plate 30 on which the locking means is disposed is formed withtwo colinear, elongated rectangular openings 82, 84 separated by abridge 86 lying in the plane of said plate. The locking lever is mountedon the outer face of the side plate with its arch 72 resting on thebridge 86 and with the reaches 74, 76 located in the openings 82, 84respectively. When the blade is locked in either closed or openposition, the front reach 76 is substantially coplanar with the sideplate 30. At such time the rear reach 74 extends away from the sideplate at a slight angle, thus elevating the button 80 and providing aspace for the latters depression. Said button protrudes through anopening 88 in the knife scale 26 so that it can be depressed manually toelevate the front reach on which the locking dog is carried.

When the blade is locked, the locking dog projects inwardly from theside plate 30 and the locking spring 70 normally biases the dog to suchposition. Said spring is in the form of a substantially flat strip ofspring steel having an elongated oblong central aperture 90 running oversubstantially its full length. The rear end 92 of the spring is caughtbeneath an L-shaped tang 94 struck from the side plate, said tangextending through the aperture 90. The spring is of such length that,with its rear end 92 thus held, its forward end is adjacent the sideplate 30 and bridges the aperture 84. With this arrangement said end 96rests on and presses the reach 76 of the locking lever toward the spacebetween the side plates.

The locking indentations 64, 66 are disposed on substantiallydiametrically opposite sides of the pivot aperture 52 in the tang of theknife blade. These apertures are so located that when the knife isclosed one of them lies beneath the locking dog 78, and when the bladeis fully opened the other indentation lies beneath the locking dog.Thus, either in closed or open position the locking dog, urged by thelocking spring 70 into one or the other of the locking indentations,will hold the blade against rotation.

To prevent the button from being depressed accidentally, a safety catch98 is included. As shown herein, said safety catch is fashioned from asingle piece of resilient strip metal. One branch 100 of the safetycatch is narrow and rests flat against the side plate, being locatedwithin the aperture 90 of the locking spring. The rear end of the branch100 is connected by a return bend 102 to a top branch 104 substantiallyparallel to the branch 100 but about equal in width to the lockingspring. Said top branch includes a nub 106 which projects through anopening 108 in the scale 26. Said opening is elongated to permit thesafety catch to be reciprocated lengthwise of the knife by manipulationof the nub. The forward end of the top branch 104 is bifurcated to forma pair of spaced fingers 110 whose tips are fashioned with downward tips112 which ride on the longitudinal edges of the locking spring 70. Whenthe safety catch is slid forwardly, it will embrace the shank of thepush button below the enlarged head thereof and said fingers with theirdownturned tips will prevent the head of the push button from beingdepressed.

It is pointed out that by imparting to the locking lever the specialshape described, it can, despite being made from flat stock, permit theinsertion of the safety catch under the head of the push button, disposethe push button perpendicular to the knife frame when the lock iseffective and yet secure a substantial depth of engagement between thelocking dog and locking indentations. Such construction thereforeenables a substantial saving in manufacturing costs to be achievedwithout in any way interfering with the efficiency and appearance of theknife. It also will be understood that a locking lever of the foregoingconstruction can be fabricated rapidly in mass production and to closetolerances with the aid of speedy and comparatively simple metalfashioning machinery.

Inspection of the shapes of the locking indentations 64, 66 shows thatthe same are of substantially uniform overall depth and are bounded bysteep sides so that an appreciable degree of engagement between theindentations and the locking dog may be brought about without exposingthe locking indentations in either open or closed position of the knifeblade.

Pursuant to the invention, the locking indentations are fashioned in theknife blade by stamping. This method permits speedy, inexpensive andaccurate forma tion of the indentations in the blades and enables thedepth of the indentations to be independent of their length so that theindentations can be both as deep and as long as desired. This is incontrast to the previous formations of the indentations by millingwherein the length and depth were interrelated. Moreover, by forming theindentations by stamping the number of handling operations is reducedand the accuracy in positioning of said indentations is increased.

In Figs. 1 through 6 there is indicated an apparatus 120 and process forcarrying out the latter phase of the invention. Said apparatus comprisesan intermittent feed means, such as a pair of intermittently actuatedrolls 122, 124, arranged to advance a flat stock strip 126. Said striphas a width corresponding either to the width or length of the knifeblade to be made, preferably the former. As is conventional, the stockstrip is of high carbon steel and usually is very hard, e. g. of anorder of hardness 100 Rockwell C. The stock is fed through a guide 128to a stamping machine 130 whose anvil 132 is at the level of the bed ofthe guide. The stamping machine is of the progressive operation typehaving three sets of dies 134, 136 and 138.

The die 134 punches a through opening 140 in the stock in a region whichsubsequently will be the center of a locking indentation 66.

The die 136 includes a punch 142 which forms the pivot opening 52. Italso includes a pair of punches 144,

146 which indent the locking indentations 64, 66. The

punch 146 operates on the stock immediately adiacent a longitudinal edgethereof so that, despite the extreme hardness of the stock, the metalthereof can flow outwardly a short distance sufficient to permitformation of the indentation 64. Flow of metal during formation of theindentation 66, which is well within the boundaries of the stock, isaccommodated by the opening 140.

The die 138 constitutes a blanking punch in the shape of the knifeblade. This punch separates from the strip a blank blade 148 havingformed therein the pivot opening 52 and indentations 64, 66. The bladesubsequently is ground to its finished shape.

The anvil 132 is provided with suitable openings matching the die 134,the punch 146 and the die 138.

In addition to the advantages mentioned above concerning the fabricationof the locking indentations by stamping, i. e. obtaining any desireddepth of locking indentation without a concomitant increase in length,stamping of the indentations has the additional advantage that itenables the indentations to be made without several handling operations.Thus, if the indentations are milled, it is necessary to set the bladesup in a milling machine twice. Each of these set-ups must be veryaccurate because the locking indentations are quite close to the pivotopening and yet must control with reasonable accuracy the position ofthe tip of the blade which is many times farther away from the pivotopening. When the locking indentations are made by stamping, the samecan be located with the desired degree of accuracy in the same machinethat the blades are blanked and without any additional handlingoperations or set-ups. This has resulted in a very large reduction ofmanufacturing costs and has speeded up fabrication of blades of the typeunder consrderation.

It may be mentioned that the intermittent feed imparted to the strip bythe rolls 122, 124 is slightly in excess of the overall width of ablade, as is conventional. All of the punches are carried by the samereciprocating head 150. A stripper 152 aids in disengaging the severaldies from the stock.

It thus will be seen that there is provided a device which achieves allthe objects of the invention and is well adapted to meet the conditionsof practical use.

As various possible embodiments might be made of the above invention,and as various changes might be made in the embodiment above set forth,it is to be understood that all matter herein described, or shown in theaccompanying drawings, is to be interpreted as illustrative and not in alimiting sense.

Having thus described the invention, there is claimed as new and desiredto be secured by Letters Patent:

1. A push-button fly-blade knife comprising a knife frame including aside plate constituting a wall of a knife blade compartment, a knifeblade, means to pivotally secure an end of said blade to the side plate,means to resiliently urge said blade from closed to open position, saidblade being swingable substantially 180 between open and closedposition, and means to lock said blade in either closed or openposition, said last-named means comprising a pair of stamped lockingindentations on said blade on opposite sides of the pivotal securingmeans and equidistant therefrom, a sheet metal locking lever, a pair ofapertures in the side plate spaced apart by a bridging portion of saidplate, one of said apertures being disposed above one of the lockingindentations when the blade is in closed position, said locking leverincluding an arched portion which is seated on the bridge portion of theside plate and a pair of reaches extending away from said arched portionand extending toward and away from the pivotal securing means, the reachwhich extends toward the pivotal securing means being disposed at anangle to the reach portion which extends away from the pivotal securingmeans, said last-named reach portion being inclined away from thesurface of the side plate that is remote from the knife bladecompartment when the locking means is effective and terminating in aplatform parallel to the first-named reach por tion, said first-namedreach portion terminating in a locking dog which is disposed at a levelmore inwardly of the knife frame than said first-named reach portion,said dog being disposed in one or the other of the locking indentationswhen the locking means is effective, means to bias said first-namedreach portion toward said knife compartment, and a push button mountedon said platform, said push button extending perpendicularly outwardlyaway from said platform.

2. A push-button fly-blade knife comprising a knife frame including aside plate constituting a wall of a knife blade compartment, a knifeblade, means to pivotally secure an end of said blade to the side plate,means to resiliently urge said blade from closed to open position, saidblade being swingable substantially 180 between open and closedposition, and means to lock said blade in either closed or openposition, said last-named means comprising a pair of lockingindentations on said blade on opposite sides of the pivotal securingmeans and equidistant therefrom, a sheet metal locking lever, a pair ofapertures in the side plate spaced apart by a bridging portion of saidplate, one of said apertures being disposed above one of the lockingindentations when the blade is in closed position, said locking leverincluding an arched portion which is seated on the bridge portion of theside plate and a pair of reaches extending away from said arched portionand extending toward and away from the pivotal securing means, the reachwhich extends toward the pivotal securing means being disposed at anangle to the reach portion which extends away from the pivotal securingmeans, said last-named reach portion being inclined away from thesurface of the side plate that is remote from the knife bladecompartment when the locking means is effective and terminating in aplatform parallel to the first-named reach portion, said first-namedreach portion terminating in a locking dog which is disposed at a levelmore inwardly of the knife frame than said first-named reach portion,said dog being disposed in one or the other of the locking indentationswhen the locking means is effective, means to bias said first-namedreach portion toward said knife compartment, and a push button mountedon said platform, said push button extending perpendicularly outwardlyaway from said platform.

3. For use in a push-button fly-blade knife comprising a knife frameincluding a side plate constituting a wall of a knife blade compartment,a knife blade, means to pivotally secure an end of said blade to theside plate and means to resiliently urge said blade from closed to openposition, said blade being swingable substantially between open andclosed position: means to lock said blade in either closed or openposition, said lastnamed means comprising a pair of stamped lockingindentations on said blade on opposite sides of the pivotal securingmeans and equidistant therefrom, a sheet metal locking lever, a pair ofapertures in the side plate spaced apart by a bridging portion of saidplate, one of said apertures being disposed above one of the lockingindentations when the blade is in closed position, said locking leverincluding an arched portion which is seated on the bridge portion of theside plate and a pair of reaches extending away from said arched portionand extending toward and away from the pivotal securing means, the reachwhich extends toward the pivotal securing means being disposed at anangle to the reach portion which extends away from the pivotal securingmeans, said lastnamed reach portion being inclined away from the surfaceof the side plate that is remote from the knife blade compartment whenthe locking means is effective and terminating in a platform parallel tothe first-named reach portion, said first-named reach portionterminating in a locking dog which is disposed at a level more inwardlyof the knife frame than said first-named reach portion, said dog beingdisposed in one or the other of the locking indentations when thelocking means is effective, means to bias said first-named reach portiontoward said knife compartment, and a push button mounted on saidplatform, said push button extending perpendicularly outwardly away fromsaid platform.

4. For use in a push-button fly-blade knife comprising a knife frameincluding a side plate constituting a wall of a knife blade compartment,a knife blade, means to pivotally secure an end of said blade to theside plate and means to resiliently urge said blade from closed to openposition, said blade being swingable substantially 180 between open andclosed position: means to lock said blade in either closed or openposition, said lastnamed means comprising a pair of locking indentationson said blade on opposite sides of the pivotal securing means andequidistant therefrom, a sheet metal locking lever, an aperture in theside plate above a position occupied by one of the locking indentationswhen the blade is in closed position, means to pivotally mount saidlever on said plate adjacent said aperture, said lever including a pairof reaches extending away from said pivotal mounting means and extendingtoward and away from the pivotal securing means, the reach which extendstoward the pivotal securing means being disposed at an angle to thereach portion which extends away from the pivotal securing means, saidlast-named reach portion being inclined away from the surface of theside plate that is remote from the knife blade compartment when thelocking means is effective and terminating in a platform parallel to thefirst-named reach portion, said firstnamed reach portion terminating ina locking dog which is disposed at a level more inwardly of the knifeframe than said first-named reach portion, said dog being disposed inone or the other of the locking indentations when the locking means iseffective, means to bias said firstnamed reach portion toward said knifecompartment, and a push button mounted on said platform, said pushbutton gxtending perpendicularly outwardly away from said platorm.

5. For use in a push-button fly-blade knife comprising a knife frameincluding a side plate constituting a wall of a knife blade compartment,a knife blade, means to pivotally secure an end of said blade to theside plate and means to resiliently urge said blade from closed to openposition, said blade being swingable substantially 180 between open andclosed position: means to lock said blade in either closed or openposition, said lastnamed means comprising a pair of locking indentationson said blade on opposite sides of the pivotal securing means andequidistant therefrom, a sheet metal locking lever, a pair of aperturesin the side plate spaced apart by a bridging portion of said plate, oneof said apertures being disposed above one of the locking indentationswhen the blade is in closed position, said locking lever including anarched portion which is seated on the bridge portion of the side plateand a pair of reaches extending away from said arched portion andextending toward and away from the pivotal securing means, the reachwhich extends toward the pivotal securing means being disposed at anangle to the reach portion which extends away from the pivotal securingmeans, said first-named reach portion terminating in a locking dog whichis disposed at a level more inwardly of the knife frame than saidfirstnamed reach portion, said dog being disposed in one or the other ofthe locking indentations when the locking means is effective, means tobias said first-named reach portion toward said knife compartment, and apush button mounted on the free end of said second-named reach portion.

6. For use in a push-button fly-blade knife comprising a knife frameincluding a side plate constituting a wall of a knife blade compartment,a knife blade, means to pivotally secure an end of said blade to theside plate and means to resiliently urge said blade from closed to openposition, said blade being swingable substantially 180 between open andclosed position: means to lock said blade in either closed or openposition, said lastnamed means comprising a pair of stamped lockingindentations on said blade on opposite sides of the pivotal securingmeans and equidistant therefrom, a locking lever including a lockingdog, means to pivot said lever on said side plate, an aperture in saidside plate through which said dog passes, said aperture being disposedabove one of the locking indentations when the blade is in closedposition, means to pivotally attach said locking lever to said sideplate, a push button carried by said locking lever, and means to urgesaid locking lever in a direction for said dog to engage one or theother of said indentations.

7. For use in a push-button fly-blade knife having a locking dog, meansmounting the dog for movement between two positions, and means to urgethe dog to one of said positions: a knife blade, means to mount saidknife blade pivotally for movement between two positions, means to urgethe blade to one of said positions, said blade having a pair of stampedlocking indentations on opposite sides of the pivotal mounting means andequidistant therefrom, one of said indentations when the knife blade isin one of its positions being in the position to which the dog is urgedand the other of said indentations when the knife blade is in the otherof its positions being in the position to which the dog is urged.

8. In a method of making a push-button fiy-blade for a knife: thatimprovement constituting the steps of forming a pair of indentations ina metal strip by stamping, and subsequently stamping a blade out of saidstrip with said indentations locatedin the tang of the blade in positionfor use as locking indentations.

9. In a method of making a push-button high-carbon fly-blade for aknife: that improvement constituting the steps of forming a throughopening in a metal strip, thereafter stamping a locking indentationadjacent said opening, and subsequently stamping a blade out of saidstrip with said indentation located in the tang of the blade in positionfor use as a locking indentation.

References Cited in the file of this patent UNITED STATES PATENTS969,909 Schrade Sept. 13, 1910 1,135,863 Tolputt Apr. 13, 1915 1,357,398Haywood Nov. 2, 1920 1,413,633 Tanner Apr. 25, 1922 2,183,378 ConklinDec. 12, [939 2,304,601 Schrade Dec. 8, 1942 2,434,268 Hartkopf Jan. 13,1948

